Pneumatically powered applicator



p 1968 K. G. DOWNING 3,401,847

PNEUMATI CALLY POWERED APPLI CATOR Filed April 5, 1967 2 Sheets-Sheet 1a0 a We /4 I111 llllllllllllln o H o o /Ke/7/7e 2% 6. flown/ 9 INVENTOR.

BY Magda & PM!

P 1968 K. G. DOWNING PNEUMATICALLY POWERED APPLICATOR- 2 Sheets-Sheet 2Filed April 3, 1967 United States Patent O 3,401,847 PNEUMATICALLYPOWERED APPLICATOR Kenneth G. Downing, Houston, Tex., assignor toThermon Manufacturing Company, a corporation of Texas Filed Apr. 3,1967, Ser. No. 628,079 6 Claims. (Cl. 222-327) ABSTRACT OF THEDISCLOSURE A pneumatically powered applicator having a manuallyactivated valve to utilize compressed air to successfully move anapplicator plunger or piston to extrude the contents of the cylinderthrough an output nozzle.

BACKGROUND OF THE INVENTION (1) Field of the inventin.The inventionpertains in general to the controlled application of a composition to agiven environment and in particular to the application, in discreteamounts, of a heat transfer material to a steam tracer line or otherheating element generally used in maintaining a material transferconduit at a given temperature. As is well known, such heat transfermaterial is used in certain industries where materials are conveyed fromone processing point to another through pipelines or the like. Thepneumatic applicator of the present invention is particularly suitablefor applying heat conductive material. As will be appreciated from thefollowing description, the applicator of the present invention is alsosuitable for use in the controlled application of calking compositions,lubricants, or any other semifluid substance.

(2) Description of the prior art.Heretofore, mechanically actuatedcalking guns have been used for applying heat transfer material and thelike. Although hand powered mechanical guns are satisfactory for use forshort periods of time, they are too tiring for continuous use overprolonged periods of time.

SUMMARY OF THE INVENTION The construction of the present applicatorutilizes operator control but with a minimum of manual effort so that itmay be used without causing the operator to become excessively fatigued.Further, it is economical in that it is fabricated using many of thestructural components of a standard, manually operated calking gun. Theworking components of the applicator of the present invention arecommercially accessible and may be repaired or replaced with relativeease. In contrast to many prior art devices, the entire applicator unitis self-contained and portable, requiring only a source of compressedair for power.

The pneumatic power supplied to the applicator is converted into areciprocating mechanical movement by introducing the compressed air intoa cylindrical chamber which drives a spring-loaded power piston. A rodattached to the power piston drives a double pawl and ratchet mechanismwhich in turn drives a second piston or plunger through the applicatorcylinder containing heat transfer material or other semifluidcomposition for extruding the composition from a nozzle at the end ofthe applicator cylinder.

It is thus an object of the present invention to provide BRIEFDESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation of a first form ofthe pneumatic applicator of the present invention;

3,401,847 Patented Sept. 17, 1968 FIG. 2 is a partial vertical sectionillustrating several operating details of the applicator of FIG. 1;

FIG. 3 is a vertical section illustrating several additional operatingdetails of a slightly modified embodiment of the pneumatic applicator ofthe present invention; and

FIG. 4 is a horizontal section taken along the line 44 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The applicator of thisinvention includes a loading or applicator cylinder 10 connected to ahandle 11. A power cylinder 12 is mounted above the loading cylinder 10.The handle 11 carries an air valve 13 which may be opened or closed byactuation of a valve trigger 13a. One side of the valve 13 is connectedby an air line 14 to the power cylinder 12. The other side of the valve13 is connected to a supply line 15 which in turn is connected to asource (not illustrated) of compressed air.

As best illustrated in FIGS. 2 and 3 of the drawingss, the compressedair from the supply line 15 enters the air line 14 through the air valve13 where it is then introduced into a chamber 12a in the power cylinder12. The pressure of the air in the chamber 12a displaces a power piston16 aganst the force of a spring 17, When the chamber 12a isdepressurized, the spring 17 restores the piston 16 to its rest position(to the right in FIG. 3). An opening 12b is provided in a removable capat the end of the power cylinder 12 to vent the air contained within thecylinder 12 between the piston 16 and the cap 12a. A piston rod 16atransmits the movement of the piston 16 to a drive arm 18 through a pin18a. In the preferred embodiment, the power cylinder 12 is adapted topivot slightly about a pivot pin 24 to accommodate the arcuate movementof the pin 18a relative to the drive arm 18. The drive arm 18 ispivotally secured at its lower end to the handle 11 by a pivot pin 18b.

As illustrated in FIGS. 3 and 4, a spring loaded pawl 19 is pivotedabout a pivot pin 19a secured to the drive arm 18. A spring 19b ismounted on the outer ends of the pivot pin 19a (FIGS. 3 and 4) and isconfined under compression between the lower surface of the pawl 19 andthe forward surface of the arm 18 so as to exert a constant resilientforce tending to pivot the pawl 19 clockwise (FIG. 3) to hold it incontact with the ratchet teeth 20b while allowing the pawl 19 to pivotcounterclockwise enough for the pawl 19 to move rearwardly (to the rightin FIG. 3) relative to the teeth 20b when the arm 18 is retracted to theright (FIG. 2). A second spring-loaded backup pawl 21 is pivoted about apin 21a and also engages the teeth 20b. The pawl 21 is urged resilientlyinto constant contact with the rachet teeth 20b by a compressed spring21b which has its intermediate portion coiled about the ends of thepivot pin 21a and has its ends in engagement with the lower surface ofthe pawl 21 and a stop 21c secured to the handle 11. Thus, the pawl 21is urged in a clockwise direction about its pivot pin 21a, but it maypivot slightly in a counterclockwise direction (FIG. 3) to allow theteeth 20b to move forwardly or to the left relative to the pawl 21. Therod 20a is removably secured at one end to a plunger 20 carried withinthe applicator cylinder 10. The other end of the rod 20a has a handle21c so as to facilitate retraction of the plunger 20 (to the right inFIG. 3) after the rod 20a has been partially rotated to disengage theratchet teeth 2012 from the pawls 19 and 21, as will be more fullyexplained.

As viewed in FIG. 3 of the drawings, movement of the drive arm 18 to theleft is transmitted to the rod 20a through the pawl 19. When the rod 20amoves to the left, the backup pawl 21 merely slips over the ratchetteeth 20b. Movement of the arm 18 to the right draws the pawl 19 to theright in a slipping movement over the teeth 20]). The rod 20a isprevented from moving to the right as the pawl 19 moves to the rightbecause the engagement of the backup pawl 21 in a notch of the teeth20]) locks the rod 20a against such movement.

The pawls 19 and 21 may be disengaged from the teeth 20b by partiallyrotating the rod 20, generally about 90 from the engaged positionillustrated in FIG. 3 of the drawings to the released positionillustrated in FIG. 1. When the teeth 20b have been thus disengaged, therod 20 may be moved by hand in either direction in the cylinder 10.

The form of the applicator illustrated in FIG. 3 of the drawings isadapted to be employed with a disposable cylindrical cartridge 22 whichis prefilled with a heat transfer cement or other material 23.Preferably, the cylinder has a forward removable cap 30 which isthreaded at 30a to the cylinder 10 or is otherwise remo-vably securedthereto. The cap 30 has an aperture 30b therethrough. At the other endof the cylinder 10, a removable cap 31 is preferably threaded thereto at31a, and it has an opening 31b through which the rod a extends.

The cartridge 22 is of conventional construction and is usually providedat one end with a nozzle 22a and at its other end with a movable disk22b or similar element. As the plunger 20 advances to the left in FIG.3, the element 22b is forced along the inside of the cartridge 22 by theplunger 20, causing the material 23 to be extruded through the nozzle22a which projects outwardly through the opening b. The cap 30 may bedisengaged from the applicator cylinder 10 and the cartridge 22 may bereplaced after the contents 23 have been dispensed therefrom. When a newcartridge 22 is being inserted into the loading cylinder 10, the piston20 is restored to its starting position by turning the handle 200 todisengage the teeth 20b from the pawls 21 and 19 so that a smoothportion of the rod 20a may slide over the pawls 19 and 21.

The embodiment illustrated in FIG. 2 of the drawings is the same as thatof FIG. 3 except that the material 23 is placed directly in the bore ofthe cylinder 10 rather than in the separate cartridge 22. In themodification of FIG. 2, the piston 120 has an outside diametercorresponding to the inside diameter of the cylinder 10. The cylindercap 130 has an attached or integrally formed nozzle 13%. Thus, theapplicator of this invention may be readily adapted for either cartridgetype loading or cylinder loading of the material to be dispensed.

FIG. 2 includes a schematic illustration of the air valve 13 which issecured to the handle 11 by bolt or rivet 13 It should be understoodthat the illustrated form of the valve 13 is exemplary and any valvecapable of providing the desired function may be employed. The valve 13is spring loaded so that is closed in its off or rest position (FIG. 2and dotted line position of FIG. 3). When a trigger 13a is squeezed oractuated to its on position (solid line position of FIG. 3), it rotatesa cylindrical valve gate 13b to cause a central passage 130 to registerwith the opening 15a in the supply line 15 and an opening 14a in the airline 14. With the form of the valve 13 illustrated in FIG. 2 of thedrawings, the chamber 12a in the power cylinder 12 remains pressurizeduntil the trigger 13a is released. The release of the trigger 13a allowsa spring 13d to restore the valve gate 13b to the off or rest positionwhere the chamber 12a may be vented through a channel 13a in the valvegate 13b. Each opening and closing of the valve 13 produces only onecycle or stroke of movement of the piston 16. If desired, the valve 13may be replaced by a valve mechanism which will continuously open andclose to produce repetitive strokes of the piston 16 automatically solong as the trigger 13a remains depressed. In such a modification, thepiston 20 would continue to advance through the applicator cylinder 10until the valve trigger 13a is released.

In operating the embodiment illustrated in FIGS. 1 and 2 of thedrawings, the handle 200 is first rotated to disengage the pawls 19 and21 from the teeth 20b. The handle 200 is drawn to the right to positionthe piston at the extreme right-hand end of the cylinder 10. The end capis then removed and the cylinder 10 is filled with material 23. The endcap 130 is replaced and the handle 20c is rotated to re-engage the pawls19 and 21 with the teeth 2%. The nozzle 13% is then positioned in thedesired area and the trigger 13a is pulled into the handle 11. Theplunger 120 advances a distance determined by the stroke of the piston16 and thus for each stroke of the piston 16, a quantity of the material23 is extruded through the nozzle 13Gb.

In the embodiment illustrated in FIG. 3 of the drawings, the smallerpiston 20 is positioned at the extreme right of the cylinder 10 bydisengaging the teeth 20.: and the pawls 19 and 21 and pulling the rod20a to the right. The end cap 30 is removed, a full cartridge 22 ispositioned in the cylinder 10, and the cap 30 is replaced. The operatorplaces the nozzle 22a in the desired position and squeezes the trigger13a. Such squeezing takes only a minimum of effort and may beaccomplished with one finger if desired. The piston 20 moves apredetermined amount to advance the movable disk 22b through cartridge22, causing a quantity of the material 23 to extrude through the nozzle22a for each stroke of the piston 16.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, and materials as well as in the details of the illustratedconstruction may be made within the scope of the appended claims withoutdeparting from the spirit of the invention.

I claim:

1. An applicator for applying putty-like material to a desired work areacomprising:

(a) an applicator cylinder for containing a putty-like material;

(b) a plunger disposed in said applicator cylinder for longitudinalmovement relative thereto for dispensing the semifiuid material from thecylinder;

(c) pneumatic power means for longitudinally moving said plunger withinsaid applicator cylinder;

((1) movement transmission means operably connecting said pneumaticpower means to said plunger for imparting only forward movements to theplunger from the pneumatic power means for effecting the dispensing ofthe material in said applicator cylinder; and

(c) said pneumatic power means including:

(1) a piston movable for a forward stroke by fluid pressure suppliedthereto;

(2) resilient means to return said piston after its forward stroke;

(3) a drive arm pivotally connected to said piston; and

(4) a power pawl mounted on said drive arm for movement with said drivearm.

2. The applicator of claim 1 including:

(a) a handle on said applicator cylinder so that the entire applicatormay be manually held by a user;

(b) valve means for said pneumatic power means including trigger meansfor opening and closing said valve means; and

(0) means mounting said valve means with said handle.

3. The applicator of claim 1 wherein:

(a) said applicator cylinder is adapted to receive a cartridgecontaining said putty-like material and having a nozzle therewith;

(b) said plunger being slidably received in the rearward end of saidcartridge for forcing the material therein from the nozzle as saidplunger moves longitudinally relative to said cylinder; and

(c) said cylinder having a centrally apertured removable end cap throughwhich said cartridge nozzle extends.

4. The applicator of claim 1 including:

(a) an end cap removably disposed at the forward end of said applicatorcylinder; and

(b) an integrally formed nozzle with said end cap through which saidmaterial in said cylinder is dispensed.

5. The structure set forth in claim 1 wherein said movement transmissionmeans includes:

(a) ratchet teeth on said rod engageable by said power pawl for movingsaid rod forwardly while slipping relative thereto as said power pawl ismoved rearwardly upon the return of said piston by said resilient means;and

(b) a backup pawl also engageable with said ratchet teeth for preventingsaid rod from being moved rearwardly as said power pawl movesrearwardly.

' 6 6. The structure set forth in claim 1, including: (a) a powercylinder for said piston mounted with said applicator cylinder; and (b)means pivotally mounting said power cylinder on said applicator cylinderfor relative pivotal movement thereof as said drive arm reciprocates.

References Cited UNITED STATES PATENTS 2,815,151 12/1957 Collins 222-3272,923,442 2/ 1960 Maras 222-391 X 2,995,159 8/1961 Berggren 222-334 X2,998,289 8/ 1961 Runciman 222-39l X SAMUEL F. COLEMAN, PrimaryExaminer.

